Is it possible to assign static MAC addresses to specific users? (Server is using MS-SSTP)

Post your questions about SoftEther VPN software here. Please answer questions if you can afford.
Post Reply
Arin
Posts: 3
Joined: Mon Sep 18, 2017 1:28 am

Is it possible to assign static MAC addresses to specific users? (Server is using MS-SSTP)

Post by Arin » Wed Mar 14, 2018 6:50 pm

Hello, I am currently running a small personal SoftEther server on Windows 10 using MS-SSTP as the main VPN protocol. The server is working fine, but when I tried to add another user, I noticed this problem.

It seems that the MAC addresses are automatically generated and assigned based on the "connection order" of the client, regardless of the username or full session ID (which is kinda contrast to the search results I found). Automatic creation and assignment is not really a problem - actually a necessity in this case - but I would like to retain "same MAC address for the same user/session", to facilitate easier DHCP IP assignment, even when the virtual Hub is restarted. For example, in my case, this happend the last day:

Client 1 (let's say username A), which connects first, is given a specific MAC address of CA-A1-11-11-11-11 (a fictional address to illustrate my point)
Client 2 (username B), which connects second, is given CA-B2-22-22-22-22

Now, the virtual hub underwent restart due to some power outage

Client 1 (with username A) reconnects, and is given CA-A1-11-11-11-11 (expected behavior; no problem)

However, when client 3 (not 2; with username C) connects, it is given CA-B2-22-22-22-22, not some new MAC address. This created a problem for my DHCP server, which gave the IP originally designed to be given to B. What I expected was it receiving something like CA-C3-33-33-33-33.

From a two-hour search on the forum and the Internet, I found no valid workaround to this problem. My search found that:
viewtopic.php?f=7&t=42065&p=59298&hilit=MAC#p59298
viewtopic.php?f=7&t=8651&p=54235&hilit=MAC#p54235
viewtopic.php?f=7&t=8743&p=23348&hilit=MAC#p23348
And from the code (https://github.com/SoftEtherVPN/SoftEth ... on.c#L2340), I see that it is supposed to assign some hashed MAC address based on the machine's name (remains the same over any number of sessions), virtual hub's name (of course this is static and should be identical across all users on that hub), and the unique session ID. However, there seems to be no way to force assign a specific MAC address based on the username.

What I want, again, is to retain the same MAC address for the same user/client, whether by manual configuration (configuration option) or by automatic generation rule. There is *no* need to actually obtain and relay the actual MAC address of the client (as the third search hit), though it is acceptable as an alternative as long as no additional software/driver installation is required.

I am not a programmer (only took a basic, rudimentary introductory course - something like CS101 - in my undergraduate years, which is at least 13 years ago) and have no ability to read and understand all through the whole code. I am presuming that if that unique session ID is the whole string (ex. SID-USERNAME-[SSTP]-n) except the ending n, it should work... but it seems that USID is the last n. Maybe by including some option to include username instead of cardinal session numbering, my issue can be tackled (the another solution would be a way/option to assign specific MAC address to a given user account, if possible, by any means).

Or, is there some other way that I could not find? If so, please kindly tell me.

Thank you, and have a nice day.

thisjun
Posts: 2458
Joined: Mon Feb 24, 2014 11:03 am

Re: Is it possible to assign static MAC addresses to specific users? (Server is using MS-SSTP)

Post by thisjun » Thu Mar 29, 2018 4:52 am

I think static MAC address can be generated by username.
However, if some sessions use same username, those MAC address will conflict.

slim8020
Posts: 5
Joined: Thu Aug 23, 2018 12:02 pm

Re: Is it possible to assign static MAC addresses to specific users? (Server is using MS-SSTP)

Post by slim8020 » Fri Aug 24, 2018 8:36 am

You do not have the required permissions to view the files attached to this post.

Post Reply